no it is the jack for the external speaker without a doubt. On a speaker jack when you plug in an external speaker it will disconnect the internal speaker and play thru the external speaker only. I plugged the external speaker in ( without looking ) and screwed up the jack so the external was not able to connect properly... when I removed the external speaker it would not play thru the internal speaker because the metal tab that disconnects the internal speaker did not reconnect. so no speaker was connected to the radio. I did not have the time for a repair and wanted to sell quickly. after opening the radio and taking pictures and bending the little metal tab into place the internal speaker works fine. I would not plug an external speaker back in because the jack is not 100%. The radio is in the box and packed with all acessories for another day. I have kenwood,Icom,yaesu,general,yeticom,and several others and hand helds also.After buying 500 in coax 450 in a power supply and switch boxes rotors and towers and conduit to bury coax I don't have time to even think of selling the radio. they are good radios.If you can find one. If I was going to buy a radio for SSB get a ham radio and get the mod done.AM only get a good 40 channel cobra etc for 100.00 and call it a day. thanks